Publications

Objective: To investigate the association between clinical, biomechanical, and psychosocial factors and smiling behavior in individuals with treated unilateral cleft lip with or without cleft palate (UCL ± P) compared to non-cleft controls.

Design: Multicenter observational study in New Zealand.

Participants: Individuals aged ≥15 (N = 42) comprised 2 study groups: a UCL ± P group (N = 21) and a non-cleft control group (N = 21).

Methods: Participants viewed an amusing video while their facial expressions were recorded. Smile features were automatically detected via software. A clinical outcome, nasolabial esthetics, was scored using the Asher-McDade system. Perioral biomechanical properties were measured via myotonometry. Smile Esthetics-related Quality of Life (SERQoL), Orofacial Esthetics Scale (OES), and personality (IPIP-NEO-60) questionnaires were completed.

Results: Smile features and personality traits did not differ between the groups. Participants with UCL ± P exhibited higher stiffness (+44.2%; Cohen’s d = 1.6) and tone (+22.6%; Cohen’s d = 1.9) at the cleft scar site, and higher decrement (or lower elasticity, +8.5%; Cohen’s d = 0.8) adjacent to the scar. Nasolabial esthetics and elasticity of the scar correlated with the duration of smiles and relative smile time (−0.50 < R < −0.44; p < .05). Participants in the UCL ± P group had lower scores for the OES and higher impacts on SERQoL for social contacts and dental self-confidence.

Conclusions: Adolescents and adults with UCL ± P exhibit similar smile behavior as their cleft-free peers – at least in non-social settings. Nasolabial esthetics and perioral biomechanical properties are associated with propensity to smile. UCL ± P is negatively associated with smile-related quality of life and an individual’s perception of their facial appearance.

Keywords: artificial intelligence, assessment, cleft lip, lip function, orthodontics, quality of life, young adults, scarring

Automated analysis of smile episodes showed no differences in smile features amongst adolescents and adults who had undergone treatment for a UCL ± P, in comparison to a control group. This indicates that people with UCL ± P exhibit similar smile behavior as the general population – at least in non-social settings. However, unsatisfactory nasolabial AM scores and low elasticity of the cleft scar were found to be linked to a diminished tendency to smile. As a result of this research, we have demonstrated that myotonometry is a valid clinical tool to objectively assess the physical properties of cleft scars and the perioral musculature. Interestingly, while psychosocial factors, including self-perceived smile esthetics-related quality of life and orofacial esthetics, were notably negatively impacted within the UCL ± P group, they did not demonstrate any association with smile outcomes. In light of these lower self-reported factors, we advocate for the provision of continuous psychosocial support for adults affected by UCL ± P.